Abstract
Strengthening of connections in steel framed structures is often required to mitigate the risk of progressive collapse initiated by column removal event. Steel framed buildings with simple shear connections between beams and columns are vulnerable to progressive collapse. Therefore, strengthening such structural systems for existing buildings as well as the designing of robust connections in the new structures is vital. This study was undertaken with the prime objective of investigating experimentally and numerically the efficient strengthening schemes for simple shear beam-column connections in order to minimize the risk of collapse in the incidence of sudden column loss. The experimental and numerical study includes testing a control test frame of a one-third scale single story shear-connection sub-assemblage consisting of two bays. A steel frame with an intermediate moment frame (IMF) connection was used as a target frame. Two schemes of strengthening beam-column connections were adopted for upgrading the control frame. The first scheme employed welded double side plates within the connection region, and the second scheme used pretensioned high-strength hot-rolled steel rods within the connection region. All specimens were subjected to dynamic loading in the vertical direction which essentially simulates extreme load cases like an explosion in which columns are removed. The efficacy of the strengthening schemes was evaluated based on the results of experiments and numerical simulation of the tested specimens.